Although wastewater treatment is becoming increasingly important for sustainable environmental protection, it is still not guaranteed or is insufficient in many parts of the world.

Only about 20 percent of the wastewater produced worldwide is treated. A drastic reduction in global water pollution is urgently needed. Progressive climate change with increasing soil sealing is leading to flooding, which is becoming increasingly difficult to control due to inadequate or poorly maintained drainage systems.

Before wastewater can be disposed of above or below ground or discharged into water bodies, it must be properly treated. Appropriate treatment is necessary to prevent contamination of receiving waters.